Spatial distribution and population dynamics of Callichirus major (Crustacea, Callianassidae) in a tropical sandy beach, northeastern Brazil

Abstract

AbstractCallichirus major is a callianassid shrimp widely used as live bait by Brazilian recreational fishers. Here, we present information about spatial distribution and population dynamics of C. major based upon both the number of burrow openings and the number of specimens collected monthly between July 2011 and September 2012 at Aruanda Beach, northeastern Brazil. Burrows occupied a spatial area between 68 m (November 2011) and 107 m wide (April 2012), starting at the intermediate intertidal area (~48 ± 5 m below the high tide mark) and extending their distribution to the sublittoral zone. Mean density ranged from 5.6 ± 3.6 (December 2011) to 35.6 ± 18.7 burrows per m2 (July 2012). The population had a female‐biased sex ratio (1:1.5 males:females). Dorsal oval length was 3.97–14.65 mm for males and 4.31–16.30 mm for females. Weight–length relationships for males and females were both allometrically positive. Ovigerous females occurred from November 2011 to March 2012, with a mean fecundity of 2327 ± 1290 eggs, and recruitment was observed in June 2012. The von Bertalanffy growth parameters estimated for males were: L∞ = 15.00 mm, K = 0.78/year, C = 0.2, and WP = 0.6. For females, the model parameters were: L∞ = 16.50 mm, K = 0.78/year, C = 0.2, and WP = 0.6. The total instantaneous mortality rate for males and females was 1.72 and 1.11/year, respectively. The pattern of distribution, density, and reproductive cycle was similar to that reported for the species in southern‐southeastern Brazil. However, the asymptotic lengths estimated here for both males and females were higher, suggesting an underexploited status for this population, inhabiting an area where penaeid shrimps are the most preferred live bait used by local recreational fishers.